A rare form of hereditary autism has been discovered and scientists think that it may be treatable with protein supplements since it is linked to an amino-acid deficiency. The genome sequencing of six children with autism revealed mutations in a gene that stops several amino acids from being depleted. Mice lacking this gene developed neurological problems, related to autism spectrum disorder, which can be reversed by dietary changes.
The scientists published their findings in the journal Science. This could be the first treatable form of autism, states Joseph Gleeson, a child neurologist at the University of California, San Diego, and lead author of the study. It could reveal the underlying mechanisms of autism.
However, mutations are likely to account for a very small amount of all autism cases. It won’t have implications for patients in general, and there’s yet no proof that dietary supplements will help the children whose mutations were identified by sequencing the exome.
Three of the children’s parents were first cousins. This makes hunting for the rare recessive mutations that underlie some forms of autism much simpler than among the general population, since the odds are higher that these children will be born with two copies of the recessive mutation.
The team identified mutations that inactivated the enzyme BCKD-kinase, which prevents the body from breaking down amino acids after a meal. The human body cannot synthesize these amino acids, and must obtain them from food.
It’s still a mystery how this amino acid deficiency causes autism. Branched-chain amino acids enter the brain through specialized transporters through the blood-brain barrier. The transporter proteins also shuttle other large amino acids into the brain. When levels of the amino acids are low, more of these molecules are allowed through.
Gleeson hypothesizes that the symptoms of this kind of autism are caused by low levels of branched-chain amino acids, high levels of other amino acids, or a combination of these two factors.
This chemical imbalance is treatable in mice when they were put on a diet enriched in branched-chain amino acids. The children’s imbalance was also treated in this fashion, but there is yet no proof that their autism symptoms got better.
In a properly controlled clinical trial, the researchers hope to see whether dietary supplements ease the children’s symptoms.
Reference: “Mutations in BCKD-kinase Lead to a Potentially Treatable Form of Autism with Epilepsy” by Gaia Novarino, Paul El-Fishawy, Hulya Kayserili, Nagwa A. Meguid, Eric M. Scott, Jana Schroth, Jennifer L. Silhavy, Majdi Kara, Rehab O. Khalil, Tawfeg Ben-Omran, A. Gulhan Ercan-Sencicek, Adel F. Hashish, Stephan J. Sanders, Abha R. Gupta, Hebatalla S. Hashem, Dietrich Matern, Stacey Gabriel, Larry Sweetman, Yasmeen Rahimi, Robert A. Harris, Matthew W. State and Joseph G. Gleeson, 6 September 2012, Science.
DOI: 10.1126/science.1224631
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3 Comments
This is promising. But only for those with a unique form of autism. We need more research! Hopefully in the future we can find a bigger solution for those on the spectrum. Or is it just too complicated of a disorder to have that easy of a blanket solution?
I’m autistic my name is John I’ve suffered with social anxiety all my life with the help of strattera and propranolol I’m recovering I also have a loving relationship with a woman which helps me very much I will recover
I have a young son who we found out five years ago, is Autistic. He has Asperger’s on the Spectrum. He is 41. But very small. He has never grown developmentally or physically like a regular male his age should or would. I’m a product of family secrets that have come to light as of late, over the last couple of years. You see, I’ve discovered I am of Azorean descent. My Mother’s Mother’s parents were first cousins. And came from a village called Flores in the the Spanish Azorean back in the late 1700’s- early 1800’s. At that time it was common for family members to intermarry. And have children. I’ve been studying A LOT about their cultures, etc. I recently found out that there was a disease that ravaged the island, and my great great grandparents and their children. They had eleven, and only five survived past age 15. The disease is called Machado- St Joseph’s Disease. I got tested two years ago and the tests came back positive. I know for sure that my son has it, but there are no genetic clinics here that will test him. I’ve researched and read up on all the genetics about the chromosomes, and testing and that there is no cure for this disease. Only medicines that doctors can make the effects from seizures, blood clots, gait syndromes, etc, less of a burden. I’ve been doing all I can to keep up on all the new research that the Drs and scientists are doing as far as ASD too. Eric has been on every medicine known to man since he was 12, all they do is make him sicker. He loses body weight, can’t keep food down, he gets acid reflux, diarrhea, it’s a horror show. Im waiting for the day, when there will be a Dr or scientist that will come up with the medicine that will help my son. Before it’s too late.